This is, of course false.

I did some SIR modeling last year that predicted the pandemic would burn out in about 6 months, assuming we kept containment in Wuhan City or Hubei province. Since we obviously messed that up, my model was wildly wrong.

Your model, while perhaps wildly wrong to describe the US in general (or the world in general), will likely describe regions accurately (with separate parameters for each region): the coastal cities of the US are largely ok now, while the American South and the inter-mountain West not so much. Africa is, of course, a human-made disaster.

So it’s important to remember that the overall vaccination rate is irrelevant, but the vaccination rate in each particular community is highly relevant.

As to your assumption of R0 ~ 7: this post contains a terrifying plot of US vaccination rates vs Trump/Biden popular vote, on a county-by-county basis. What’s interesting is that it puts herd immunity to the Delta variant at 85% vaccination (or immunity from previous COVID-19). That translates to R0 ~ 6.7. I would have thought that a bit high, but it is based on some data coming out of the Yale School of Medicine, so maybe that’s the case.

So a while ago I would have thought your estimate of R0 too pessimistic. But now I fear that you are correct: this is probably the case. (“The optimist proclaims that we live in the best of all possible worlds; and the pessimist fears this is true.” — James Branch Cabell, The Silver Stallion: A Comedy of Redemption)